Progress and Perspective of Near-Ultraviolet and Deep-Ultraviolet Light-Emitting Diode Packaging Technologies

Abstract Ultraviolet light-emitting diodes (UV-LEDs) have drawn considerable attention in environment, life science, and industry fields, such as the applications of near UV-LEDs in resin curing, illumination, and identification, and deep UV-LEDs in disinfection, medical treatment, and biochemical inspection. However, due to the limitation of packaging technology, UV-LED devices exhibit low light efficiency and poor reliability compared with visible LEDs. The organic encapsulation materials are prone to UV aging, thermal degradation, and nonairtightness, which significantly reduce the performances of UV-LEDs. In order to solve this issue, UV-LED packaging technology has been proposed for UV-LED devices instead of conventional LED packaging. In this review, we investigated in detail the overview and challenges of near-ultraviolet light-emitting diodes (NUV-LED)/deep-ultraviolet light-emitting diodes (DUV-LED) packaging. For the packaging of UV-LEDs, all inorganic encapsulation materials, hermetic packaging structures with low-temperature bonding, reduced reflection losses, UV stable and transparent materials, and effective thermal management are key progresses to enhance the light efficiency and reliability of UV-LEDs. In addition, the summary and perspectives of NUV-LED/DUV-LED packaging were introduced and discussed.

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ACCURATE MEASUREMENT OF ULTRAVIOLET LIGHT-EMITTING DIODES

10.25039/x48.2021.op43 ◽

2021 ◽

Author(s):

C. Yuqin Zong ◽

Cameron Miller

Keyword(s):

Ultraviolet Light ◽

Light Emitting Diodes ◽

Luminous Flux ◽

Junction Temperature ◽

Integrating Sphere ◽

Light Emitting ◽

Type D ◽

Uv Led ◽

Uv Leds ◽

Ultraviolet Light Emitting Diodes

We have developed a new calibration capability for 200 nm to 400 nm ultraviolet light-emitting diodes (UV LEDs) using a Type D gonio-spectroradiometer. The recently-introduced mean differential continuous pulse (M-DCP) method is used to overcome the measurement difficulty associated with the initial forward voltage, VF, anomaly of a UV LED, which makes it impossible to use VF to infer junction temperature, TJ, during pulsed operation. The new measurement facility was validated indirectly by comparing the measured total luminous flux of a white LED with that measured using the NIST’s 2.5 m absolute integrating sphere. The expanded calibration uncertainty for the total radiant flux is approximately 2 % to 3 % (k = 2) depending the wavelength of the UV LED.

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Light Efficiency Enhancement of Deep Ultraviolet Light-Emitting Diodes Packaged by Nanostructured Silica Glass

Journal of Display Technology ◽

10.1109/jdt.2016.2564986 ◽

2016 ◽

Vol 12 (10) ◽

pp. 1106-1111 ◽

Cited By ~ 11

Author(s):

Yang Peng ◽

Simin Wang ◽

Hao Cheng ◽

Han Wang ◽

Mingxiang Chen ◽

...

Keyword(s):

Ultraviolet Light ◽

Silica Glass ◽

Light Emitting Diodes ◽

Efficiency Enhancement ◽

Light Emitting ◽

Deep Ultraviolet ◽

Nanostructured Silica ◽

Ultraviolet Light Emitting Diodes ◽

Light Efficiency

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Irradiation by a Combination of Different Peak-Wavelength Ultraviolet-Light Emitting Diodes Enhances the Inactivation of Influenza A Viruses

Microorganisms ◽

10.3390/microorganisms8071014 ◽

2020 ◽

Vol 8 (7) ◽

pp. 1014

Author(s):

Mizuki Kojima ◽

Kazuaki Mawatari ◽

Takahiro Emoto ◽

Risa Nishisaka-Nonaka ◽

Thi Kim Ngan Bui ◽

...

Keyword(s):

Ultraviolet Light ◽

Influenza A ◽

Light Emitting Diodes ◽

Strongly Correlated ◽

Influenza A Viruses ◽

Light Emitting ◽

Uv Led ◽

Uv Lamp ◽

Uv Leds ◽

Ultraviolet Light Emitting Diodes

Influenza A viruses (IAVs) pose a serious global threat to humans and their livestock. This study aimed to determine the ideal irradiation by ultraviolet-light emitting diodes (UV-LEDs) for IAV disinfection. We irradiated the IAV H1N1 subtype with 4.8 mJ/cm2 UV using eight UV-LEDs [peak wavelengths (WL) = 365, 310, 300, 290, 280, 270, and 260 nm)] or a mercury low pressure (LP)-UV lamp (Peak WL = 254 nm). Inactivation was evaluated by the infection ratio of Madin–Darby canine kidney (MDCK) cells or chicken embryonated eggs. Irradiation by the 260 nm UV-LED showed the highest inactivation among all treatments. Because the irradiation-induced inactivation effects strongly correlated with damage to viral RNA, we calculated the correlation coefficient (RAE) between the irradiant spectrum and absorption of viral RNA. The RAE scores strongly correlated with the inactivation by the UV-LEDs and LP-UV lamp. To increase the RAE score, we combined three different peak WL UV-LEDs (hybrid UV-LED). The hybrid UV-LED (RAE = 86.3) significantly inactivated both H1N1 and H6N2 subtypes to a greater extent than 260 nm (RAE = 68.6) or 270 nm (RAE = 42.2) UV-LEDs. The RAE score is an important factor for increasing the virucidal effects of UV-LED irradiation.

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